The specific aims of the proposed work are to study: 1. The role of gonococcal pili in the host-parasite relationship; a. The role of pili in the sticking of gonococci to mammalian cells; b. Characterization of the mammalian receptor of gonococcal pili; c. Species and organ distribution of the pilus receptor; 2. Immunochemical analysis of the outer membrane of the gonococcus; a. Further studies on the purification of the outer membrane; b. characterization of low molecular weight outer membrane protein.